Some vehicles are supplied with side airbag devices. Generally the device is located along a side of the vehicle and deploys an inflatable curtain in accordance with a predetermined activation occurrence. The side impact air bags or inflatable cushions are often mounted in close proximity to the vehicle's roof rail, doorframe or center pillars, or in some instances within the side door. Accordingly, the space or housing for the un-inflated airbag is compact and extends or traverses along the window area or frame, as the airbag cannot be installed in the areas comprising the window. Moreover, it is also desirable to have the inflatable cushion disposed behind a decorative trim portion of the vehicle's interior. Thus, the presence of the side airbag device is not observable to occupants when it is in its un-deployed state.
When the air bag or inflatable cushion is mounted to the vehicle the top edge portion is fixed and a lower edge portion, which defines the bottom periphery of the airbag, deploys out of the storage location positioned in close proximity to the roof rail. Furthermore, and referring in particular to larger or longer vehicles (e.g., sports utility vehicles, vans, mini-vans, station wagons, etc.) a single side air bag or inflatable cushion that extends from the A pillar to the D pillar, or further, of the vehicle has to have an extended length to cover the side areas of the vehicle. Accordingly, these extended inflatable cushions require additional inflator output in order to inflate and maintain the inflation of the cushion for a pre-determined period of time.
In addition, and due to the location of deployment of these cushions (e.g., vehicle side, A-D pillars) it is desirable to provide these cushions with an extended period of inflation. Moreover, and depending on the vehicle type other areas of the cushion that traverse across the interior of the vehicle (e.g., between doors) may not require inflation. However, these areas still comprise a portion of the inflatable cushion. The required extended period of inflation may comprise up to and exceeding five seconds. These extended periods of inflation allow the inflatable cushion to provide a retentive barrier across the opening of the windows of the vehicle. In order to provide inflation cushions which retain their inflation gases for extended periods of time the cushion in one configuration is provided with sealed seams in accordance with U.S. Pat. No. 6,220,309, the contents of which are incorporated herein by reference thereto. Alternatively, sealed cushions are provided by disposing sealing material such as silicone between the edges of two sheets of fabric members comprising the inflatable cushion. In addition, these types of cushions (e.g., less permeable cushions or cushions that retain inflation gases for extended periods of time) are expensive to manufacture. Accordingly, side impact inflation cushions become larger in order to cover extended lengths and their associated costs increase.
Accordingly, it is desirable to provide a cost-efficient sealed inflatable cushion that is capable of staying inflated for an extended period of time as well as being able to traverse and extend the length of the vehicle.